Thank you for your reply @mpaladin .
Unfortunately it is not a build/analysis issue (and I was able to have successful build/analysis when running the docker containers locally in interactive mode). This also excludes the second suggestion (permission error) as it worked in interactive mode.
BUT in the process of researching other options/causes I discovered that there are general issues with alpine linux and UnixFileSystem.canonicalize0 JNI call.
Sources:
https://discourse.metabase.com/t/problem-while-building-custom-image/14985
https://forums.docker.com/t/builds-with-alpine-linux-3-14-fail-on-docker-hub/112469/4
In the latest Dockerfile of the sonar-scanner-cli-docker image the following base-image is used: adoptopenjdk/openjdk11:alpine-jre
The solution for me was to build the image from scratch and swapping the base-image for a debian based one: adoptopenjdk/openjdk11:debian-jre
(I had to adapt the dependency install - “apk” commands replaced with “apt”, different package names.)
Now everything works as it is supposed to. I hope this will also help others 